Rubber Build up on Inside

[daltvater]

Does this look normal to you all?

Front wheels. 2.5 degrees camber.

Doesn't look like pickup, looks like the rubber being pushed to the outside to the inside.

2.5 degrees feels right to me but maybe not enough?

[daltvater]

[Walt Fricke]

Try this again. "to the outside to the inside"??
This a 911? Front? Which tire are we looking at? LF? Outside showing at bottom or top of picture?
The top of the tire in the picture clearly the highest wear area, so that is the outside? In which case more camber might even the wear, as the bottom looks less worn under the clag.

[daltvater]

Originally Posted by Walt Fricke

Try this again. "to the outside to the inside"??
This a 911? Front? Which tire are we looking at? LF? Outside showing at bottom or top of picture?
The top of the tire in the picture clearly the highest wear area, so that is the outside? In which case more camber might even the wear, as the bottom looks less worn under the clag.

Walt, thanks for the help. I think I met you probably 15+ years ago at LaJunta or Pueblo? Had a 87 Targa at the time and was just learning the ropes.

So both front tires look like this. The bottom of the photo is the inside of the tire. The car was aligned the week before this wear.

The rears look perfect. In looking at the alignment sheet the rears are at 2.5 degrees and the fronts are at 3 degrees.

The car has a 935 type coil over conversion with a 3.6, straight cut, low ratio gear box. Goes like hell

[Walt Fricke]

You might try getting tire temperatures - outside, center, inside.
Your alignment sheet looks like you have 3 degrees negative front, and about 2.5 rear. No such thing as caster at the rear.

3 degrees negative front looks like a good number for the track, but if your wear is on the outside, why not go for more negative if it is available?

I'm assuming this is a 964 or earlier? Set up for the track.
My approach to camber isn't all that scientific - I keep adding until the tire wear outside/inside is about equal.

Toe can cause uneven wear, but your toe settings don't look like they are likely culprits.

We could well have met back then. I was instructing (still am).

Let's hope someone who pays more attention to his alignment chimes in. I'm a Hoosier guy.

[3rd_gear_Ted]

Was the track surface cold or warm?

[flat6pilot]

Just curious, but what are you running for tire pressure? With those year 911's listed on your sheet, I'd expect you'd be in the 24 to 27psi range on cold tires on those (R888's??). Hot should put you somewhere in the low 30's. Too high or low can affect the wear, too.

That buildup on the inside looks like it's picking up rubber from the track.

[daltvater]

Edited below

[daltvater]

Originally Posted by Walt Fricke

You might try getting tire temperatures - outside, center, inside.
Your alignment sheet looks like you have 3 degrees negative front, and about 2.5 rear. No such thing as caster at the rear.

3 degrees negative front looks like a good number for the track, but if your wear is on the outside, why not go for more negative if it is available?

I'm assuming this is a 964 or earlier? Set up for the track.
My approach to camber isn't all that scientific - I keep adding until the tire wear outside/inside is about equal.

Toe can cause uneven wear, but your toe settings don't look like they are likely culprits.

We could well have met back then. I was instructing (still am).

Let's hope someone who pays more attention to his alignment chimes in. I'm a Hoosier guy.

1979 with 935 coilover setup.

Originally Posted by 3rd_gear_Ted

Was the track surface cold or warm?

Coldish resulted in the buildup. Hot day last week and the tires wore perfectly.

Originally Posted by flat6pilot

Just curious, but what are you running for tire pressure? With those year 911's listed on your sheet, I'd expect you'd be in the 24 to 27psi range on cold tires on those (R888's??). Hot should put you somewhere in the low 30's. Too high or low can affect the wear, too.

That buildup on the inside looks like it's picking up rubber from the track.

I'm running about 24-25 hot on a set of AR-1's Love that tire. 50 heat cycles, 1000+ miles. Still putting down the same lap times as the beginning. I like them more than r888rs and Nt-01's

[flat6pilot]

Originally Posted by daltvater

50 heat cycles, 1000+ miles. Still putting down the same lap times as the beginning. I like them more than r888rs and Nt-01's

Is that after doing their break-in heat cycle recommendation? Running a few laps then letting cool for at least 24hrs?

[daltvater]

Originally Posted by flat6pilot

Is that after doing their break-in heat cycle recommendation? Running a few laps then letting cool for at least 24hrs?

Skipped the break-in part. Just drove them hard from the beginning. Put down my best lap last session out. Pretty impressive tire which is good because its about the only option I have over here in NZ.